You may cite Section 10(26) of the Income Tax Act 1961, which provides as under, and explain that you / you income, staisfy the conditions prescrbed therein:
[(26) in the case of a member of a Scheduled Tribe as defined in clause (25) of article 366 of the Constitution, residing in any area specified in Part I or Part II of the Table appended to paragraph 20 of the Sixth Schedule to the Constitution or in the States of Arunachal Pradesh, Manipur, Mizoram, Nagaland and Tripura] or in the areas covered by notification No. TAD/R/35/50/109, dated the 23rd February, 1951, issued by the Governor of Assam under the proviso to sub-paragraph (3) of the said paragraph 20 [as it stood immediately before the commencement of the North-Eastern Areas (Reorganisation) Act, 1971 (81 of 1971)] or in the Ladakh region of the State of Jammu and Kashmir], any income which accrues or arises to him,—
(a) from any source in the areas [or States aforesaid], or
(b) by way of dividend or interest on securities;